Extranuclear Acylation or Carboxylation

This reaction is a useful way to make some alkyl pyrazinyl ketones or car-boxyalkylpyrazines, as illustrated in the following examples  

3-Dimethylpyrazine gave 2-hexanoylmethyl-3-methylpyrazine (304) (Pr 2NLi, Et20, 175°C, 30 min Et02C(CH2)4Me, -78°C, 30 min 70%) analogues likewise.352 

6- Tetramethylpyrazine gave 2-carboxymethyl-3,5,6-trimethylpyrazine (monolithiation in situ then C02 [, Et20, 0°C, 39 min 95%, as the Li salt).1384 

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